Viscous damping of roll during entry of a Mars entry and landing capsule

Viscous damping in roll of blunt body and hemisphere-cone forebody during planetary entr

Electric vehicle chassis dynamometer test methods at JPL and their correlation to track tests

Early in its electric vehicle (EV) test program, JPL recognized that EV test procedures were too vague and too loosely defined to permit much meaningful data to be obtained from the testing. Therefore, JPL adopted more stringent test procedures and chose the chassis dynamometer rather than the track as its principal test technique. Through the years, test procedures continued to evolve towards a methodology based on chassis dynamometers which would exhibit good correlation with track testing. Based on comparative dynamometer and track test results on the ETV-1 vehicle, the test methods discussed in this report demonstrate a means by which excellent track-to-dynamometer correlation can be obtained

A review of aerodynamic noise from propellers, rotors, and lift fans

Hand calculation procedures for predicting aerodynamic noise from propellers, rotors, and lift fan

Low subsonic dynamic-stability investigation of several planetary-entry configurations in a vertical wind tunnel, part i

Low subsonic dynamic stability data for evaluation of ballistic deceleration vehicle entering Mars atmospher

Financial incentives and study duration in higher education

The current paper investigates to which extent students in higher education respond to financial incentives by adjusting their study behavior. Students in Norway who completed certain graduate study programs between 1991 and 1995 on stipulated time were entitled to a restitution (of approximately 3,000 USD) from the Norwegian State Educational Loan Fund. Using a difference-in-difference approach, we find that the fraction of students graduating on time during the reform period increased by 10 percent, relative to a base probability of about 25 percent. The estimated effect for fully treated students (students who were aware of the reform from the start of their studies) is much higher, at 50 percent.

Restricting the Miranda Presumption and Pruning the Poisonous Tree: Oregon v. Elstad

The Elstad decision is significant because the Court eliminated the fruit of the poisonous tree doctrine with regard to Miranda violations, if the secondary evidence is a subsequent confession. As a result of Elstad, before a court will apply the derivative evidence rule to the secondary evidence, a suspect in custody must prove there was actual coercion by the police when they obtained the initial statement. This Note will discuss the Elstad decision and the impact it will have on criminal procedure

Wind Field and Trajectory Models for Tornado-Propelled Objects

A mathematical model to predict the trajectory of tornado born objects postulated to be in the vicinity of nuclear power plants is developed. An improved tornado wind field model satisfied the no slip ground boundary condition of fluid mechanics and includes the functional dependence of eddy viscosity with altitude. Subscale wind tunnel data are obtained for all of the missiles currently specified for nuclear plant design. Confirmatory full-scale data are obtained for a 12 inch pipe and automobile. The original six degree of freedom trajectory model is modified to include the improved wind field and increased capability as to body shapes and inertial characteristics that can be handled. The improved trajectory model is used to calculate maximum credible speeds, which for all of the heavy missiles are considerably less than those currently specified for design. Equivalent coefficients for use in three degree of freedom models are developed and the sensitivity of range and speed to various trajectory parameters for the 12 inch diameter pipe are examined

A mobile Magnetic Sensor Unit for the KATRIN Main Spectrometer

The KArlsruhe TRItium Neutrino experiment (KATRIN) aims to measure the electron neutrino mass with an unprecedented sensitivity of 0.2 eV/c2, using b decay electrons from tritium decay. For the control of magnetic field in the main spectrometer area of the KATRIN experiment a mobile magnetic sensor unit is constructed and tested at the KATRIN main spectrometer site. The unit moves on inner rails of the support structures of the low field shaping coils which are arranged along the the main spectrometer. The unit propagates on a caterpillar drive and contains an electro motor, battery pack, board electronics, 2 triaxial flux gate sensors and 2 inclination senors. During operation all relevant data are stored on board and transmitted to the master station after the docking station is reached.Comment: 11 pages, 14 figure

Avalanches in a Bose-Einstein condensate

Collisional avalanches are identified to be responsible for an 8-fold increase of the initial loss rate of a large 87-Rb condensate. We show that the collisional opacity of an ultra-cold gas exhibits a critical value. When exceeded, losses due to inelastic collisions are substantially enhanced. Under these circumstances, reaching the hydrodynamic regime in conventional BEC experiments is highly questionable.Comment: 4 pages, 2 figures, 1 tabl